/Engine/Source/Runtime/SlateCore/Public/Input/HittestGrid.h
Set the position and size of the hittest area in desktop coordinates
Returns true if a clear of the hittest grid was required.
bool SetHittestArea ( const [UE::Slate::FDeprecateVector2DParameter](API\Runtime\SlateCore\Types\FDeprecateVector2DParameter) & HittestPositionInDesktop, const [UE::Slate::FDeprecateVector2DParameter](API\Runtime\SlateCore\Types\FDeprecateVector2DParameter) & HittestDimensions, const [UE::Slate::FDeprecateVector2DParameter](API\Runtime\SlateCore\Types\FDeprecateVector2DParameter) & HitestOffsetInWindow )